I use the Schultz with an eye-dropper for everything. 14 drops in a 1/2 gallon watering can.
A lot of plants can stay alive indefinitely in just water, but to say they are growing can often be a stretch. The amount of mass that the limited amount of roots are able to support in the unusual condition is usually limited. Once it reaches that limit, old leaves will drop at about the same pace as new ones replace them.
Besides peace lily, is there a specific candidate involved?
